San Francisco park officials said it will cost $1 million to replace a popular playground at Golden Gate Park after someone torched it overnight. The search is on for whoever is responsible for the vandalism at the Koret Children's Quarter.

The playground was closed Sunday because it was so badly burned. It's now roped off with yellow caution tape. It's unclear when it will reopen because park officials aren't sure how they will get the money to replace it.

Families especially children visiting the Koret Children's Quarter at Golden Gate Park were shocked and baffled. Slides are melted and the rings and portions of a playground are charred.

"I feel kind of disappointed," said Eight-Year-Old Malia Miller. "This is one of my favorite parts of the park."

Many visitors were traveling from out of the area and it was their first time at the park.

"There's really no reason to vandalize a kid's park," said Jeffrey Tsai of Los Angeles. "They are pretty innocent."

"It's definitely disturbing," said Sarah Murphy of Sacramento. "Where I'm from we don't see many parks vandalized."

Authorities said the fire was reported at 12:30 a.m. Fire crews responded and immediately put it out. The cause is still under investigation. No one was injured.

"On an annual basis, we usually see things like broken glass, graffiti, but this is a pretty rare occurrence," said Sarah Madland, spokeswoman for the San Francisco Recreation and Parks Department.

The San Francisco Recreation and Parks Department has no idea who's responsible. The last time any of their parks was set on fire was the West Sunset Playground in 2005.

"I think it's weird that someone could even think to do it at a playground of all places," said Meredith Peck of San Francisco. "It's where small kids come to be safe and play with other kids."

Park officials said it will need to be replaced. Based on their experience of rehabbing playgrounds, they estimate it will cost $1 million. Originally opened in 1888, the Koret Children's Quarter reopened in 2007 after a $3.8 million renovation.

Despite the high cost to replace it, visitors hope it will happen soon.

"A lot of things happen that don't need to happen and this is one of those things that don't need to happen," said Jeffrey Tsai of Los Angeles. "Hopefully we find the funds to do it because I think this is a wonderful gathering place for children."

There are security cameras in the area. There will be extra patrols in light of what happened.

Anyone with information is asked to contact the San Francisco Fire Department at (415) 920-2933.